Electric switch



March 30 1926.

R. Tr KINTZING ELECTRIC SWITCH Filed April 21, 1921 2 Sheets-Sheet 1 Quw QN wm w nw mw. mw m MN M 1 Si mw nw. 5m l 1 m NN w NNW m, u@ V w i@ Vm F Ardai7 I l- 11M im Twj 1j ,1 f i} la WHA .z i J Hl MQW @mw WIK @lt N4m uw I 1 mm 1mm. Y l n WITNESSES: .-a fm A Marh 30 1926. 1,578,527

R, 'II KlNTZING ELECTRIC SWITCH Filed April 2l, 1921 2 Sheets-Sheet 2INVENTOR W ITN ESSES:

Reeselfmzy ATTORNEY Patented Mar. 30, 1926.

UNITED STATES PTNT QFFECE.

REESE T. KINTZING, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO WESTING-HOUSE ELECTRIC c MANUFACTURING COMPANY, A CGRQORATIO'N OF kPENNSYL-VANIA.

Application iileil April 21, 1921. Serial No. l163,113.

T0 all whom it may concern.'

Be it known that 1, Rasse T. KINTZING, a citizen of the United States,and a resident of vWilkinsburg, in the county of Allegheny and Stat-e ofPennsylvania, have invented a new and useful Improvement in ElectricSwitches, of which the following is a specification.

My invention relates to electrical switches and more particularly toswitches that are automatically operated through change in direction ofmovement of mechanisms with which they are associated. p

In the operation of electrically driven machinery, such as the crushingrolls in a rubber mill, in case of accidents, it is some` timesnecessary to bring the rinichinery to a sudden stop, as when a workmanbecomes caught in the rolls.

In order to effect a quick cessation of `movement, it is customary toreverse the direction of current through the motor, thus exercising ahigh degree of braking action.

However, it is not desirable to actually reverse the movement' of therolls or other machinery in which the workmen may be caught, becausegreater injury to them might thereby result. Therefore, the machinery isso constructed that two opposing rolls may be released from theirsupporting members and moved apart in order to effect the removal of anyobject caught therebetween.

The object of my invention is to provide means whereby, upon reversal ofthe curA rent through the motor, the latter will be disconnected fromthe line before its travel in reverse direction is sufficient to causeany substantial reverse movement of the machine that is drivenby themotor.

A further object of my invention is to provide a frictionally operatedswitch that is subjected to a minimum amount of wearing action when inits normal position and to generally simplify the construction andoperation of switches of this character.

In the accompanying drawing- Figure 1 is a longitudinal sectional viewof my device;

i Fig. 2 is a view thereof in end elevation, and

Figs; 3, i and 5 are' detailfviews of cern tain parte of the movablecontacteai .A members.;

pair of contactmembers 16.

transmitting motion to the movable portions of the switch mechanism, isconnected, through a coupling 9, to a motor shaft (not shown).

A pulley 10 is secured to the shaft 8 and a shoe 11 is frictionallyengaged by the pulley 10. The shoe 11 is provided with holes 12 throughwhich screws extend into a block 13. The block 13 is, in turn, providedwith a hole through which a screw 14 eX- tends. The screw 14: secures abridging, or movable, contact member 15 in proper position to serve as abridging member for a The block 13 is of insulating material, and aplate v17, also of insulating material, is 'disposed be tween the block13 and the bridging member 15. The member 13 insulates the screw 14 fromthe shoe 11, and the insulating plate 17 insulates the contact member 15from the screws that extend through the holes 12 of the shoe 11.

1n order to control the position of the shoe on the pulley 10, Iprovidea pair of bracket members 2O through the outer -ends of which a pin 21extends. This pin 21 passes through a hole 22 in the shoe 11 androtatably supports such shoe between the brackets 20. y Y

The brackets are provided with enlarged openings 23 in order that 4themovementof the brackets may not be interfered with by the shaft 8. j ,i

The brackets 2O are provided also, with slotted openings 24: at theirlower ends in order that they 'may move relatively to a pin 25. The pin25 is secured to a supporting member 26 that is carried Ain the frame 6.A screw 27 serves to maintain the lower ends of the brackets 2O inproper relative position.

A pair of pins 28 are secured to the 'brackets 20 and support a pair oftension position shown in Fig. 2. lVhen the pulley l0 is rotated 'in aclock-wise direction, the shoe is moved and stop shoulders 32 on thebrackets 2O are brought into engagement with a stop shoulder 3l of themember 26, and the circuit through the terminals 19 that are carried Abythe contact members 1G, is broken.

The springs 29 are so calibrated that, when the motor runs lforward, orin a counter clock-wise direction, and the shoe has been brought to itsupper or switchclosing position, the tension eKertedther-eon iscomparatively light, due tothe fact that the distance between the shoell and'theypin 25 has been shortened by such movement. In this position,there is practically no spring pressure upon the shoe, and theti'ictional 'engagement by thepulley tends to raisethe shoe and thebrachetsQO intoa still higher position, thus,to some extent,counter-baleneing the torce otA gravity and thereby reducing thefriction between the shoe and the pulley.

The upward movement ot the shoe is limited by stop ymembers 34 onthebrackets 2O anda-stop member lon member 26.

It the motor is reversed and the pulley 10 driven in a clock-wisedirection, the 'trictional force andthe torce ot .gravity take thesamedirection, and the'shoe will/travel downwardly"against the resistingtorce of the `spring and the friction of the relatively movable contactmembers until the abutting surfaces 32 of the brackets 2() engage thestop shoulder 3l.

Upon the starting oit the motor in its counter clock-wise, or normaldirection of movement, the force exerted by the springs 29 upon thelshoe causes vsuch frictional engagement between it and the pulley as toovercome the resistance of gravity as well as the friction of theco-operating Contact members and the bracket bearings, thus enabling thevshoe to carry the bridging member l-'t to closed position.

Il', during the operation ot the apparatus in its `forward or normaldirection an acci- 'circuit through the-contact members 16 is broken.rillie c mtact members-1G complete a circuitthrough a relay (not shown),which,

in turn, controls the motor circuit, the brealiing of the relay circuit,upon reverse movement of the apparatus, vcauses the motor circuit to bebroken and the reverse movement of the motor to cease.

It desired, the switch contact members and the 'tfiictional operatingmechanism may be locatedin a `plane below't-he axis ot the pulley4 .l0and proper tension be maintained upon the shoe in order to insuremovement thereo'fby the 4pulley 10, or, such 'parts may be located atany other position with-respect to the periphery of the pulley l0.

Various other modifications may be made in the apparatus withoutdeparting trom the spirit of the invention as defined in theaccompanying claims.

-I claim as my invention:

l. An electrical i contact making and breaking device responsive to thedirection of rotation 'of a rotatable member, comprisingY thecombination with said rotatable member, of a stationary member, a bra-keshoe bearing on said rotatable member and mounted for a limitedoscillatory movement thereon, cooperating electrical contact memberscarriediby said rotatable and stationary members, and yieldable meansresponsive to said oscillatory movement for causing the brake shoe tofrictionally engage the rotatable member `withgreater pressure at oneend of its oscillation than at the other.

Q. In combination, in a switch mechanism, a drum-like memberrotatablepin a vertical plane, a movable contact member vfrictionallyconnected to the rotatable member and adapted to be moved thereby, astop member located ina plane above the yaxis of the rotatable member,for 'limiting the 'movement of the/movable conta-ct member, a stopmember locatedvin a. .plane below the first named stop member -forlimiting the movement ot the movable contact member in the reversedirection, and means for increasing the 'trictional connection betweenthe rotatable member andthe movable contact member when the movablecontact member is adj-acent to its lower position.

3. In combination, ina switch mechanism, a drum-like member rotatable ina vertical plane, a movable contact member frictionallv'connectedto therotatable member and adapted to be moved thereby, a stop member locatedin a plane above the axis oit 'the rotatable member for limiting themoven'ient oli the movable Contact member, a stop member located ina-planebelow the first-named stop member 'l'or lii'niting the movement.oit the movable contact member :in the reverse direction, means 'torincreasing the 'trictional connection between the rotatable vmemberv andthe movable contact lmeniber when the movable contact member is adjacentto its lower position, and means vtor decreasing the trictionalconnection between the movable Contact member and the rotatable memberwhen the movable contact member is in its upper position.

4:. In a switch mechanism, abase member, a rotatable member, arelatively movable irontaet member, and means pivoted to said basemember for securing,r a rictional connection between said rotatablemember and said Contact member, whereby the angular relation betweensaid pivot, the axis of said rotatable member and said contact member isvaried in such manner as to vary the friction accordingto the directionof rotation of said rotatable member.

In a switch mechanisn'i, a base member, a rotatable member1 and a.movable Contact member having a limited oscillatory movement withrespect to said base member and 'frictionally bearing against theperiphery of said rotatable member, the construction being' such thatsaid oscillatory contact member bears harder against said rotatablemember at one end of its oscillatory movement than at the other.

G. In a switch mechanism, a base member, a rotatable member, a movableContact member having a limited oscillatory movement with respect tosaid base member and frietionally bearing against the periphery of saidrotatable member, and yieldable means eccentrically connected withrespect to said rotatable member for causing said oscillatory Contactmember to bear harder against said rotatable member at one end of itsoscillatory movement than at the other. In testimony whereof, I havehereunto subscribed my name this 12th day of April REESE T. KINTZING.

